can't load brushes

I have downloaded a number of brushes and almost none of them will load. I keep getting an error that the brush is not compatible with the current version of photoshop. I'm using CS3. This is very surprising to me that CS3 wouldn't be compatible with v7+ brushes. Is this correct or is there possibly a problem? Thanks.

Geoff,

Have you unzipped the downloads? The brush files must have an .abr extension.

Rob

Yes, I've unzipped them. I'm only trying to load .abr files. Thanks.